The present invention generally relates to magnetic recording apparatuses for recording two kinds of mutually different information signals on independent tracks of a magnetic tape, and more particularly to a magnetic recording apparatus which records two kinds of mutually different information signals on two independent tracks of the magnetic tape by simultaneously forming the two independent tracks by use of two rotary magnetic heads having mutually different height positions.
Presently, a helical scan type magnetic recording and/or reproducing apparatus (hereinafter simply referred to as a video tape recorder or VTR) for home use which plays a magnetic tape having a width of 1/2 inch employs the so-called low band conversion color recording and reproducing system because the recording and reproducing frequency band of the VTR for home use is relatively narrow. According to the low band conversion color recording and reproducing system, a luminance signal separated from a color video signal is frequency-modulated, and a carrier chrominance signal separated from the color video signal is frequency-converted into a frequency band lower than a frequency band of the frequency modulated (FM) luminance signal. The FM luminance signal and the frequency converted carrier chrominance signal are frequency-division-multiplexed into a frequency division multiplexed signal, and this frequency division multiplexed signal is recorded on and reproduced from the magnetic tape. Furthermore, in order to improve the tape utilization efficiency, no guard band is formed between two mutually adjacent tracks on the magnetic tape by setting rotary magnetic heads which record the two mutually adjacent tracks to have gaps of different azimuth angles.
On the other hand, in the case of a VTR for commercial use mainly for broadcasting and especially a one-body VTR for broadcasting use having a camera integrally built therein, there are demands to reduce the size and weight of the VTR and also obtain a reproduced color video signal of a high picture quality. For this reason, the VTR for commercial use employs a system wherein the luminance signal and the color signal are recorded on and reproduced from independent tracks of a magnetic tape having the same width as that used in the VTR for home use by independent rotary magnetic heads, with a guard band formed between two mutually adjacent tracks.
The one-body VTR for broadcasting use having the camera integrally built therein employs a luminance/color (Y/C) separation recording and reproducing system according to which the luminance signal and the color difference signals are recorded on and reproduced from independent tracks of the magnetic tape. Hence, although a moire is generated in the VTR which employs the low band conversion color recording and reproducing system because the FM luminance signal and the frequency converted carrier chrominance signal are simultaneously recorded on the same track of the magnetic tape which is a non-linear transmission system, such a moire will not be generated in the one-body VTR for broadcasting use. In addition, the luminance signal and the color difference signals can be recorded and reproduced in sufficiently wide frequency bands. Moreover, since the one-body VTR for broadcasting use does not carry out a bias recording of the frequency converted carrier chrominance signal by the FM luminance signal, it is possible to improve a signal-to-noise (S/N) ratio of reproduced color difference signals. Therefore, according to the one-body VTR for broadcasting use, it is possible to obtain a reproduced color video signal of a high picture quality compared to the VTR which employs the low band conversion color recording and reproducing system.
However, the conventional one-body VTR for broadcasting use suffers a problem in that the tape utilization efficiency is poor because the guard band is provided between two mutually adjacent tracks. In addition, since an FM luminance signal and an FM color difference signal are independently recorded on the two mutually adjacent tracks, a rotary magnetic head for reproducing the FM luminance signal (or a rotary magnetic head for reproducing the FM color difference signal) will reproduce the recorded FM color difference signal (or the recorded FM luminance signal) when the rotary magnetic head traverses the guard band and scans a track which is adjacent to the intended track which is to be scanned. In the case of the one-body VTR for broadcasting use, there is no field correlation between the signals reproduced from the two mutually adjacent tracks of the magnetic tape, and it is therefore impossible to cancel the crosstalk by using the field correlation as is done in the VTR which employs the low band conversion color recording and reproducing system. As a result, the one-body VTR for broadcasting use also suffers a problem in that the crosstalk is conspicuous in the reproduced picture when the rotary magnetic head scans the track which is adjacent to the intended track which is to be scanned.
It is possible to conceive a method of reducing the crosstalk described above by independently recording a tracking signal or the like on the magnetic tape and using an automatic scan tracking device for controlling the scanning position of the rotary magnetic head responsive to the tracking signal so that the rotary magnetic head accurately scans over the intended track. However, in this case, it is necessary to additionally provide the automatic scan tracking device in the VTR, and the circuit construction of the VTR becomes complex. Furthermore, there is a problem in that the VTR becomes expensive.